In an image forming device such as an electrophotographic device and an electrostatic recording device, first, an electrostatic latent image formed on the photoconductor is developed by a toner. Next, as needed, the thus-formed toner image is transferred onto a transfer material such as a paper and then fixed by various methods such as heating, applying pressure, and solvent fume.
The above-mentioned toner obtains desired flowability and charging characteristics by attaching an external additive to the surface of colored resin particles. As the external additive, fine particles composed of an inorganic or organic material are widely and generally used.
A toner is disclosed in Patent Literature 1, which is characterized in that the liberation rate of liberated mother particles to which silica is not attached, is set to be 10% or less, and the liberation rate of liberated silica, which is silica that is not attached to the mother particles, is set to be 0.2% to 10%. Also, Patent Literature 1 describes that the toner can improve low-temperature fixability, with preventing toner filming on toner-contact members.